Process of producing oxids.



H. L. DOHERTY.

PROCESS OF PRODUCING OXIDS.

APPLICATION FILED OOT.14,1908.

Patented July 13, 1909.

In ven (or W, %w q A tty:

HENRY L. DOHERTY, OF NEW YORK, N. Y.

PROCESS OF PRODUCING OXIDE.

I Specification of Letters Patent.

manta July 13, 1509- Application filed October 14, 1908. Serial No. 407,721?

To all whom it may concern:

Be it known that I, HENRY L. DOHERTY, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented a certain new and useful Process of Producing Oxids and I do hereby declare the following to be a full,

clear, and exact description of the same, such as will enable others skilled in the art to which it appertai'ns to make and use the same.

This invention relates to processes of producing oxids and consists in a method of oxireadily ground to impalpa le powder for use in pigments and like purposes. Such oxids furthermore have distinctive tints. They are also highly reactive and well suited for chemical purposes-such as the purification of gas, clarification of water and the like. These oxids on ex osure to higher temperatures lose more or ess of their water, assuming other tints, and become 'much less reactive, assuming the aged condition. In this aged condition the ultimate molecules apparently unite more or less to form polymerids or condensed; roducts, and amass of theoxid as a wholeis ess fine-grained.

*Inthe present invention hydrated oxids of iron are produced by re ulated oxidationof metallic IIOII'by IIIOIG or ess diluted air, that is air diluted to contain a less than normal amount of oxygen under controlled temperature conditions andin the presence of 'moisture. From-the roduct so obtained, other hydrates and oxi of iron may be obtained by careful heating 'to produce products of different tints.

Iron'in the form of chips, shavings,-filings andthelike constituted forms doesnot readily andquickly oxidize-by simple ex osure to the atmosphere, even when-moist;t1is-being in part dueto the dissipation of theheat of oxidation by the atmosphere and in-part due to the'fact-that-no good circulation of air through the mass of comminu'tedironis-poss-ible. When such a mass is confined in containers in a moist state and air forced through it, on the other hand, ;the it -"erature is apt to rise to such an extent that products are formed which are -i,-rre ularl oxidized and wholly or partially dehy rate; Under such circumstances, oxidation is very apt to he -too rapid and irregular. I

It is the purpose of the present -i-nventien to provide a simple, cheap and ready method of producing uniformly oxidized and hydrated, low-tern erature oxidation products of iron in a condrtionin which-suchn odu'ots will be eminentl reactive, or will e unaged and will e very finegrained, being suitable -foras or water purification -or for pigments. this invention, the comnnnuted iron in the form of chips, shavings, filings, bor'ings or the Zlike-is placed in a suitable container, the mass being made porous if necessary by admixture of-shavings or the like, "moistened and a current of air driven through. As the temperature begins to rise b oxidation of the iron, the pure air is rep aced by air moreor less-diluted by indiflerent gases, the dilution being proportional to the observed tendency of .the temperature to rise above a certain predetermined point, and, to facilitate keeping this fixed point,

such air being cooler or warmedsomWhat,

as circumstance may dictate. v-eniently, the iron is contained in a-closed vessel having a closed air circuit com rising a tan or other forcing mechanism, a 1 eater and a-coole'r. FB furtherprovidingsuch-air circuit-with-anin et on the suction side of'the fan and an outlet on-the pressure side, the per cent-of ox gen in the aircirculatingdn the closed circuit maybe readily adjusted. By continuous passage, the oxygen will "#be Very -conquickly absorbed, a single passage being often sufficient, leavin nothing but-theresidual nitrogen to circulate. B opening the outlet on the pressure side of= t e fan,-a-small amount of the nitrogen-may be allowed to esoapeandbyopening the "inlet on'the suction side a corre'spondm amount of air may be allowe'd'to enter. '1? e=ei1teringair-is of course diluted to anydesired 'extent by a the circulating nitrogen.

While other indifferent gases, :such as washed and purified 'roduetsof combustion, li hting gas and-the ikem-ay be employed as diuting a ents in lieu of nitrogen=so-pro-' dueed, suc nitrogen resulting from absorption of the oxlygen of airis convenient and permits a re atively simple operation in closed circuit. Steam is not an advantageous diluent for most purposes, unless Working under diminished pressure, since its tem erature is generally higher than is desire in the reaction chamber. Some steam may, however, beused. The reaction chamher may be kept under any desired plus or the chamber is preferably provided with the sfecial air of false bottoms, 5 and 6, shown. hese ottoms are respectively provided with the seriesof orifices, shown; the orifices 7 of the upper bottom being arranged in.

staggered relationship to the orifices 8 of the lower bottom and being larger. By suitably adjusting the relative sizes of the orificesin the two bottoms and the'distances apart of such bottoms, granular material tumbling through the upper orifices will assume the form of angle-oi-repose hillocks on the lower bottom without reaching the lower orifices and gas or air entering through such lower orifices can easily pass through the hillocks and upper'orifices. By this means, a very uniform distribution of such gas or air 40 through the mass to be treated may be sethe lower false bottom. These cured. The reaction chamber as shown is further provided with an air inlet pipe 9 communicating with its top and an air exit pipe 10 communicating wit the space below pes are further provided with valved contmuations 11 and 12 whereby any desired mixture of air and gases may be introduced and removed. Thermometers 13 provide .for observation of the temperature within the reaction chamber. I

When it is desired to work with a gas mass circulating in closed circuit, instead of using connections 11 and 12, connections 14 and 15 ma be used. Pi e 15 connectswith pipe 10 an a cooling device 16. Beyond the cooler is a pipe connection 17, connected with the suction side of fan 18 and carrying a valved air inlet 19. On the pressure side of the fan is a pipe connection 20, leading to a heater 21, containing steam pipe 22. Connection 14 carries air back to the reaction chamber through 9. Pipe 20 is provided with a valved outlet 23.

5 From the foregoing, the operation of 1 this warmed somewhat eeaeee apparatus is' readily seen. The reaction c amber isfilledwith comminuted metal,

which may be admixed with shavings or the like. necessary for orosity of the mass. The mass is wet, rei lution, such as salt solution, to hasten reaction, and a current of air passed through it by means of the fan, the air inlets and outlets on the pipe system being partly open so that,

at this stage of the operation, the mass may be treated with substantially pure air. At this stage of the o eration, the air is best y the steam ipe. As the oxygen is absorbed, the mass e ins to warm up, as will be clearly evident thermometric readings, and the inlets and outlets for air'are partly closed to insure a greater or less dilution of the air entering through the former. The dilution and the temperature adjustment by the heater and cooler shown are so managed as to keep a tolerably uniform temperature prevailing in the reaction chamber. For most purposes, in working with iron, it is best to keep the temperature at some point between 80 F.

and 120 F., as between those tem eratures an exceptionally reactive ferric by rate can be obtained. As the oxidation proceeds and the free iron disappears, the temperature tends to fall again and the dilution of 5 the air should be again diminished, finishing finally, usually, with pure air, the temperature of the gas mass being controlled by the heater and .cooler.

The hydrated oxid formed between the oo stated ranges of temperature is very reactive and forms an advantageous material for. the preparation of ferric salts with weak acids, suc as citric, tartaric, acetic, lactic and the like, as it dissolves readily, enabling the 5 production of salts suitable in medicine, dyeing, water purifying and the like. The oxid is also suitable as such for gas purification for which purpose it may be left in the origi nal reaction chamber, the gas to be treated being sent through the chamber by approriate valved connections in lieu of the diuted air used for forming such oxid. Or it may be used for clarifying water or other liquids, being light, voluminous, reactive and readily fiocculati ng suspended particles in such liquids.

Where shavings or such light organic ma- I terials have been used for giving' porosity to the mass, after oxidation the mass may be simply treated with water and the shavings floated ofi, leaving the oxid behind. j

The hydrated oxid so formed may be employed as a pigment, either as formed or after being given different tints by regulated heating and dehydration. If dried, it may be fine-ground before such dehydration to give an impalpable powder. Such impalgable powder if heated to complete dehyration gives arouge which may be used in erably with a saline'so- 70 Y the so air dilute polishing and is very advantageous for this purpose, being free of grit or dirt if the original iron was clean.

What I claim is 1. The process of producing hydrated oxid of iron which consists in oxidizing moist finely divided iron at low temperatures by a current of air diluted to carry less than the normal amount of oxygen.

2. The process of producing hydrated oxid of iron which consists in oxidizing finely divided iron moistened with a saline solution atlow tem eratures by means of a current of to carry less than the normal amount of oxygen.

3. The process of producing hydrated oxid of iron which consists in oxidizing moist finely divided iron at low tem eratures by means of a current of air dilute to carry less than the normal amount of oxygen, the dilution being directly proportional to the observed tendency of such iron to rise in tem finely divided iron by a current of air until finishing by a current of air as temperatures begin to sink.

5. The rocess of producing hydrated oxid of iron w ich consists in confining a moist body of finel divided iron in a suitable reaction cham er and circulatin a gaseous body through such iron in close circuit, excess gas being removed at one point in said circult and air admitted at another in such proportions as to roduce a diluted air, said dilution of the air y said gaseous'mass being directly roportional to the observed tendency of t e iron to rise in temperature.

In testimony whereof I afiix my signature, in the presence of two witnesses.

HENRY L. DOHERTY.

Witnesses: I

O. B. GILBERT, RUSSELL W. JoNEs. 1 

